package top.igotcha.mapreduce.wordcount;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * @time 2021/1/10
 * @auth Gotcha
 * @describe
 */
public class JobMain extends Configured implements Tool {
    @Override
    public int run(String[] strings) throws Exception {
        //创建一个任务对象
        Job job = Job.getInstance(super.getConf(), "计算单词出现次数");
        //打包到集群上面运行时候，必须要添加以下配置，指定程序的main函数
        job.setJarByClass(JobMain.class);

        //第一步：设置读取文件的类，将文件解析成key，value对
        job.setInputFormatClass(TextInputFormat.class);
        TextInputFormat.addInputPath(job,new Path("hdfs://192.168.127.110:8020/wordcount"));
        //第二步：设置mapper类
        job.setMapperClass(WordCountMapper.class);
            //设置map阶段完成之后的输出类型
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(LongWritable.class);
        //第三步，第四步，第五步，第六步采用默认方式（分区、排序、规约、分组）
        //第七步：设置reduce类
        job.setReducerClass(WordCountReducer.class);
            //设置reduce阶段完成之后的输出类型
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(LongWritable.class);
        //第八步：设置输出类以及输出路径
        job.setOutputFormatClass(TextOutputFormat.class);
        TextOutputFormat.setOutputPath(job,new Path("hdfs://192.168.127.110:8020/wordcount_out"));
        //任务是否执行成功
        boolean b = job.waitForCompletion(true);
        return b?0:1;

    }
    public static void main(String[] args) throws Exception {
        Configuration configuration = new Configuration();
        //启动一个任务
        int run = ToolRunner.run(configuration, new JobMain(), args);
        System.exit(run);
    }
}
